Smartphone

ABSTRACT

A smartphone includes a cover layer; an LCD panel which is located under the cover layer and includes a liquid crystal layer, and a first glass layer and a second glass layer between which the liquid crystal layer is placed, wherein at least a portion of a touch sensor which senses touch in a capacitive manner is located between the first glass layer and the second glass layer; a backlight unit which is located under the LCD panel; a pressure electrode which is located under the backlight unit; and a shielding member which is located under the pressure electrode.

CROSS REFERENCE TO RELATED APPLICATIONS

Priority is claimed under 35 U.S.C. §119 to Korean Patent ApplicationNo.: 10-2014-0124920, filed Sep. 19, 2014, the disclosure of which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a smartphone, and more particularly toa smartphone which includes a display module and is configured to detecta touch position and the magnitude of a touch pressure.

BACKGROUND OF THE INVENTION

Various kinds of input devices are being used to operate a computingsystem. For example, the input device includes a button, key, joystickand touch screen. Since the touch screen is easy and simple to operate,the touch screen is increasingly being used in operation of thecomputing system.

The touch screen may constitute a touch surface of a touch input deviceincluding a touch sensor panel which may be a transparent panelincluding a touch-sensitive surface. The touch sensor panel is attachedto the front side of a display screen, and then the touch-sensitivesurface may cover the visible side of the display screen. The touchscreen allows a user to operate the computing system by simply touchingthe touch screen by a finger, etc. Generally, the computing systemrecognizes the touch and the touch position on the touch screen andanalyzes the touch, and thus, performs the operations in accordance withthe analysis.

Here, there is a demand for a touch input device capable of detectingnot only the touch position according to the touch on the touch screenbut the magnitude of the touch pressure without degrading theperformance of the display module.

SUMMARY OF THE INVENTION

One embodiment is a smartphone including: a cover layer; an LCD panelwhich is located under the cover layer and includes a liquid crystallayer, and a first glass layer and a second glass layer between whichthe liquid crystal layer is placed, wherein at least a portion of atouch sensor which senses touch in a capacitive manner is locatedbetween the first glass layer and the second glass layer; a backlightunit which is located under the LCD panel; a pressure electrode which islocated under the backlight unit; and a shielding member which islocated under the pressure electrode. The touch sensor includes aplurality of drive electrodes and a plurality of receiving electrodes. Adrive signal is applied to the touch sensor and a touch position isdetected by a sensing signal which is outputted from the touch sensor. Amagnitude of a touch pressure is detected based on a capacitance changeamount outputted from the pressure electrode.

Another embodiment is a smartphone including: a cover layer; an LCDpanel which is located under the cover layer and includes a liquidcrystal layer, and a first glass layer and a second glass layer betweenwhich the liquid crystal layer is placed, wherein at least a portion ofa touch sensor which senses touch in a capacitive manner is locatedbetween the first glass layer and the second glass layer; a backlightunit which is located under the LCD panel and includes a light sourceand a reflection plate; a pressure electrode which is located under thebacklight unit; and a shielding member which is located under thepressure electrode. The touch sensor includes a plurality of driveelectrodes and a plurality of receiving electrodes. The smartphonefurther includes a drive unit which applies a drive signal to the touchsensor; a sensing unit which receives a sensing signal from the touchsensor and detects a touch position; and a pressure detector whichdetects a magnitude of a touch pressure based on a capacitance changeamount outputted from the pressure electrode.

Further another is a smartphone including: a cover layer; an LCD panelwhich is located under the cover layer and includes a liquid crystallayer, and a first glass layer and a second glass layer between whichthe liquid crystal layer is placed, wherein at least a portion of atouch sensor which senses touch in a capacitive manner is locatedbetween the first glass layer and the second glass layer; a backlightunit which is located under the LCD panel; a pressure electrode which islocated under the backlight unit; and a reference potential layer spacedfrom the pressure electrode. The touch sensor includes a plurality ofdrive electrodes and a plurality of receiving electrodes. A drive signalis applied to the touch sensor and a touch position is detected by asensing signal which is outputted from the touch sensor. A magnitude ofa touch pressure is detected based on a capacitance change amountoutputted from the pressure electrode. The capacitance change amount ischanged according to a distance between the pressure electrode and thereference potential layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a configuration of a capacitance typetouch sensor panel and the operation thereof in accordance with anembodiment of the present invention;

FIGS. 2a, 2b and 2c are conceptual views showing a relative position ofthe touch sensor panel with respect to a display module in a touch inputdevice according to the embodiment of the present invention;

FIG. 3 is a cross sectional view of the touch input device configured todetect the touch position and touch pressure in accordance with a firstembodiment of the present invention;

FIG. 4a is a cross sectional view of a touch input device according to asecond embodiment of the present invention;

FIG. 4b is an exemplary cross sectional view of a display module whichcan be included in the touch input device according to the secondembodiment of the present invention;

FIG. 5 is a perspective view of the touch input device according to thesecond embodiment of the present invention;

FIG. 6a is a cross sectional view of the touch input device including apressure electrode pattern according to the first embodiment of thepresent invention;

FIG. 6b is a cross sectional view showing a case where a pressure hasbeen applied to the touch input device shown in FIG. 6 a;

FIG. 6c is a cross sectional view of the touch input device includingthe pressure electrode pattern according to a modified example of thefirst embodiment of the present invention;

FIG. 6d is a cross sectional view showing a case where a pressure hasbeen applied to the touch input device shown in FIG. 6 c;

FIG. 6e is a cross sectional view of the touch input device including apressure electrode pattern according to the second embodiment of thepresent invention;

FIG. 6f shows the pressure electrode pattern according to the firstembodiment of the present invention;

FIG. 6g shows the pressure electrode pattern according to the secondembodiment of the present invention;

FIGS. 6h to 6i show pressure electrode patterns which can be applied tothe embodiment of the present invention;

FIG. 7a is a cross sectional view of the touch input device including apressure electrode pattern according to a third embodiment of thepresent invention;

FIG. 7b shows the pressure electrode pattern according to the thirdembodiment of the present invention;

FIG. 8 shows an attachment structure of the pressure electrode accordingthe embodiment of the present invention;

FIGS. 9a and 9b show an attachment method of the pressure electrodeaccording the second embodiment of the present invention;

FIGS. 10a to 10c show how the pressure electrode is connected to a touchsensing circuit in accordance with the second embodiment of the presentinvention;

FIGS. 11a to 11c show that the pressure electrode constitutes aplurality of channels in accordance with the embodiment of the presentinvention; and

FIG. 12 is a graph that, when an experiment where the central portion ofthe touch surface of the touch input device 1000 according to theembodiment of the present invention is pressed by the non-conductiveobject is performed, represents a capacitance change amount according toa gram force of the object.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description of the present invention shows aspecified embodiment of the present invention and will be provided withreference to the accompanying drawings. The embodiment will be describedin enough detail that those skilled in the art are able to embody thepresent invention. It should be understood that various embodiments ofthe present invention are different from each other and need not bemutually exclusive. For example, a specific shape, structure andproperties, which are described in this disclosure, may be implementedin other embodiments without departing from the spirit and scope of thepresent invention with respect to one embodiment. Also, it should benoted that positions or placements of individual components within eachdisclosed embodiment may be changed without departing from the spiritand scope of the present invention. Therefore, the following detaileddescription is not intended to be limited. If adequately described, thescope of the present invention is limited only by the appended claims ofthe present invention as well as all equivalents thereto. Similarreference numerals in the drawings designate the same or similarfunctions in many aspects.

A touch input device according to an embodiment of the present inventionwill be described with reference to the accompanying drawings. While acapacitance type touch sensor panel 100 and a pressure detection module400 are described below, the touch sensor panel 100 and the pressuredetection module 400 may be adopted, which are capable of detecting atouch position and/or touch pressure by any method.

FIG. 1 is a schematic view of a configuration of the capacitance touchsensor panel 100 and the operation thereof in accordance with theembodiment of the present invention. Referring to FIG. 1, the touchsensor panel 100 according to the embodiment of the present inventionmay include a plurality of drive electrodes TX1 to TXn and a pluralityof receiving electrodes RX1 to RXm, and may include a drive unit 120which applies a driving signal to the plurality of drive electrodes TX1to TXn for the purpose of the operation of the touch sensor panel 100,and a sensing unit 110 which detects the touch and the touch position byreceiving a sensing signal including information on the capacitancechange amount changing according to the touch on the touch surface ofthe touch sensor panel 100.

As shown in FIG. 1, the touch sensor panel 100 may include the pluralityof drive electrodes TX1 to TXn and the plurality of receiving electrodesRX1 to RXm. While FIG. 1 shows that the plurality of drive electrodesTX1 to TXn and the plurality of receiving electrodes RX1 to RXm of thetouch sensor panel 100 form an orthogonal array, the present inventionis not limited to this. The plurality of drive electrodes TX1 to TXn andthe plurality of receiving electrodes RX1 to RXm has an array ofarbitrary dimension, for example, a diagonal array, a concentric array,a 3-dimensional random array, etc., and an array obtained by theapplication of them. Here, “n” and “m” are positive integers and may bethe same as each other or may have different values. The magnitude ofthe value may be changed depending on the embodiment.

As shown in FIG. 1, the plurality of drive electrodes TX1 to TXn and theplurality of receiving electrodes RX1 to RXm may be arranged to crosseach other. The drive electrode TX may include the plurality of driveelectrodes TX1 to TXn extending in a first axial direction. Thereceiving electrode RX may include the plurality of receiving electrodesRX1 to RXm extending in a second axial direction crossing the firstaxial direction.

In the touch sensor panel 100 according to the embodiment of the presentinvention, the plurality of drive electrodes TX1 to TXn and theplurality of receiving electrodes RX1 to RXm may be formed in the samelayer. For example, the plurality of drive electrodes TX1 to TXn and theplurality of receiving electrodes RX1 to RXm may be formed on the sameside of an insulation layer (not shown). Also, the plurality of driveelectrodes TX1 to TXn and the plurality of receiving electrodes RX1 toRXm may be formed in the different layers. For example, the plurality ofdrive electrodes TX1 to TXn and the plurality of receiving electrodesRX1 to RXm may be formed on both sides of one insulation layer (notshown) respectively, or the plurality of drive electrodes TX1 to TXn maybe formed on a side of a first insulation layer (not shown) and theplurality of receiving electrodes RX1 to RXm may be formed on a side ofa second insulation layer (not shown) different from the firstinsulation layer.

The plurality of drive electrodes TX1 to TXn and the plurality ofreceiving electrodes RX1 to RXm may be made of a transparent conductivematerial (for example, indium tin oxide (ITO) or antimony tin oxide(ATO) which is made of tin oxide (SnO₂), and indium oxide (In₂O₃),etc.), or the like. However, this is only an example. The driveelectrode TX and the receiving electrode RX may be also made of anothertransparent conductive material or an opaque conductive material. Forinstance, the drive electrode TX and the receiving electrode RX may beformed to include at least any one of silver ink, copper or carbonnanotube (CNT). Also, the drive electrode TX and the receiving electrodeRX may be made of metal mesh or nano silver.

The drive unit 120 according to the embodiment of the present inventionmay apply a driving signal to the drive electrodes TX1 to TXn. In theembodiment of the present invention, one driving signal may besequentially applied at a time to the first drive electrode TX1 to then-th drive electrode TXn. The driving signal may be applied againrepeatedly. This is only an example. The driving signal may be appliedto the plurality of drive electrodes at the same time in accordance withthe embodiment.

Through the receiving electrodes RX1 to RXm, the sensing unit 110receives the sensing signal including information on a capacitance (Cm)101 generated between the receiving electrodes RX1 to RXm and the driveelectrodes TX1 to TXn to which the driving signal has been applied,thereby detecting whether or not the touch has occurred and where thetouch has occurred. For example, the sensing signal may be a signalcoupled by the capacitance (CM) 101 generated between the receivingelectrode RX and the drive electrode TX to which the driving signal hasbeen applied. As such, the process of sensing the driving signal appliedfrom the first drive electrode TX1 to the n-th drive electrode TXnthrough the receiving electrodes RX1 to RXm can be referred to as aprocess of scanning the touch sensor panel 100.

For example, the sensing unit 110 may include a receiver (not shown)which is connected to each of the receiving electrodes RX1 to RXmthrough a switch. The switch becomes the on-state in a time intervalduring which the signal of the corresponding receiving electrode RX issensed, thereby allowing the receiver to sense the sensing signal fromthe receiving electrode RX. The receiver may include an amplifier (notshown) and a feedback capacitor coupled between the negative (−) inputterminal of the amplifier and the output terminal of the amplifier,i.e., coupled to a feedback path. Here, the positive (+) input terminalof the amplifier may be connected to the ground. Also, the receiver mayfurther include a reset switch which is connected in parallel with thefeedback capacitor. The reset switch may reset the conversion fromcurrent to voltage that is performed by the receiver. The negative inputterminal of the amplifier is connected to the corresponding receivingelectrode RX and receives and integrates a current signal includinginformation on the capacitance (CM) 101, and then converts theintegrated current signal into voltage. The sensing unit 110 may furtherinclude an analog to digital converter (ADC) (not shown) which convertsthe integrated data by the receiver into digital data. Later, thedigital data may be input to a processor (not shown) and processed toobtain information on the touch on the touch sensor panel 100. Thesensing unit 110 may include the ADC and processor as well as thereceiver.

A controller 130 may perform a function of controlling the operations ofthe drive unit 120 and the sensing unit 110. For example, the controller130 generates and transmits a drive control signal to the drive unit120, so that the driving signal can be applied to a predetermined driveelectrode TX1 at a predetermined time. Also, the controller 130generates and transmits the drive control signal to the sensing unit110, so that the sensing unit 110 may receive the sensing signal fromthe predetermined receiving electrode RX at a predetermined time andperform a predetermined function.

In FIG. 1, the drive unit 120 and the sensing unit 110 may constitute atouch detection device (not shown) capable of detecting whether thetouch has occurred on the touch sensor panel 100 according to theembodiment of the present invention or not and where the touch hasoccurred. The touch detection device according to the embodiment of thepresent invention may further include the controller 130. The touchdetection device according to the embodiment of the present inventionmay be integrated and implemented on a touch sensing integrated circuit(IC, see reference numeral 150 of FIG. 10) in a touch input device 1000including the touch sensor panel 100. The drive electrode TX and thereceiving electrode RX included in the touch sensor panel 100 may beconnected to the drive unit 120 and the sensing unit 110 included in thetouch sensing IC 150 through, for example, a conductive trace and/or aconductive pattern printed on a circuit board, or the like. The touchsensing IC 150 may be located on a circuit board on which the conductivepattern has been printed, for example, a first printed circuit board(hereafter, referred to as a first PCB) indicated by a reference numeral160 of FIG. 10. According to the embodiment, the touch sensing IC 150may be mounted on a main board for operation of the touch input device1000.

As described above, a capacitance (C) with a predetermined value isgenerated at each crossing of the drive electrode TX and the receivingelectrode RX. When an object like a finger approaches close to the touchsensor panel 100, the value of the capacitance may be changed. In FIG.1, the capacitance may represent a mutual capacitance (Cm). The sensingunit 110 senses such electrical characteristics, thereby being able tosense whether the touch has occurred on the touch sensor panel 100 ornot and where the touch has occurred. For example, the sensing unit 110is able to sense whether the touch has occurred on the surface of thetouch sensor panel 100 comprised of a two-dimensional plane consistingof a first axis and a second axis.

More specifically, when the touch occurs on the touch sensor panel 100,the drive electrode TX to which the driving signal has been applied isdetected, so that the position of the second axial direction of thetouch can be detected. Likewise, when the touch occurs on the touchsensor panel 100, the capacitance change is detected from the receptionsignal received through the receiving electrode RX, so that the positionof the first axial direction of the touch can be detected.

The mutual capacitance type touch sensor panel as the touch sensor panel100 has been described in detail in the foregoing. However, in the touchinput device 1000 according to the embodiment of the present invention,the touch sensor panel 100 for detecting whether or not the touch hasoccurred and where the touch has occurred may be implemented by usingnot only the above-described method but also any touch sensing methodlike a self-capacitance type method, a surface capacitance type method,a projected capacitance type method, a resistance film method, a surfaceacoustic wave (SAW) method, an infrared method, an optical imagingmethod, a dispersive signal technology, and an acoustic pulserecognition method, etc.

The touch sensor panel 100 for detecting where the touch has occurred inthe touch input device 1000 according to the embodiment of the presentinvention may be positioned outside or inside a display module 200.

The display module of the touch input device 1000 according to theembodiment of the present invention may be a display panel included in aliquid crystal display (LCD), a plasma display panel (PDP), an organiclight emitting diode (OLED), etc. Accordingly, a user may perform theinput operation by touching the touch surface while visually identifyingan image displayed on the display panel. Here, the display module 200may include a control circuit which receives an input from anapplication processor (AP) or a central processing unit (CPU) on a mainboard for the operation of the touch input device 1000 and displays thecontents that the user wants on the display panel. The control circuitmay be mounted on a second printed circuit board (hereafter, referred toas a second PCB) (210) in FIGS. 8a to 9c . Here, the control circuit forthe operation of the display module 200 may include a display panelcontrol IC, a graphic controller IC, and a circuit required to operateother display panels 200.

FIGS. 2a, 2b and 2c are conceptual views showing a relative position ofthe touch sensor panel with respect to the display module in the touchinput device according to the embodiment of the present invention. WhileFIGS. 2a to 2c show an LCD panel as a display panel 200A included withinthe display module 200, this is just an example. Any display panel maybe applied to the touch input device 1000 according to the embodiment ofthe present invention.

In this specification, the reference numeral 200A may designate thedisplay panel included in the display module 200. As shown in FIG. 2,the LCD panel 200A may include a liquid crystal layer 250 including aliquid crystal cell, a first glass layer 261 and a second glass layer262 which are disposed on both sides of the liquid crystal layer 250 andinclude electrodes, a first polarizer layer 271 formed on a side of thefirst glass layer 261 in a direction facing the liquid crystal layer250, and a second polarizer layer 272 formed on a side of the secondglass layer 262 in the direction facing the liquid crystal layer 250. Itis clear to those skilled in the art that the LCD panel may furtherinclude other configurations for the purpose of performing thedisplaying function and may be transformed.

FIG. 2a shows that the touch sensor panel 100 of the touch input device1000 is disposed outside the display module 200. The touch surface ofthe touch input device 1000 may be the surface of the touch sensor panel100. In FIG. 2a , the top surface of the touch sensor panel 100 is ableto function as the touch surface. Also, according to the embodiment, thetouch surface of the touch input device 1000 may be the outer surface ofthe display module 200. In FIG. 2a , the bottom surface of the secondpolarizer layer 272 of the display module 200 is able to function as thetouch surface. Here, in order to protect the display module 200, thebottom surface of the display module 200 may be covered with a coverlayer (not shown) like glass.

FIGS. 2b and 2c show that the touch sensor panel 100 of the touch inputdevice 1000 is disposed inside the display panel 200A. Here, in FIG. 2b, the touch sensor panel 100 for detecting the touch position isdisposed between the first glass layer 261 and the first polarizer layer271. Here, the touch surface of the touch input device 1000 is the outersurface of the display module 200. The top surface or bottom surface ofthe display module 200 in FIG. 2b may be the touch surface. FIG. 2cshows that the touch sensor panel 100 for detecting the touch positionis included in the liquid crystal layer 250. Here, the touch surface ofthe touch input device 1000 is the outer surface of the display module200. The top surface or bottom surface of the display module 200 in FIG.2c may be the touch surface. In FIGS. 2b and 2c , the top surface orbottom surface of the display module 200, which can be the touchsurface, may be covered with a cover layer (not shown) like glass.

The foregoing has described whether the touch has occurred on the touchsensor panel 100 according to the embodiment of the present or not andwhere the touch has occurred. Further, through use of the touch sensorpanel 100 according to the embodiment of the present, it is possible todetect the magnitude of the touch pressure as well as whether the touchhas occurred or not and where the touch has occurred. Also, apart fromthe touch sensor panel 100, it is possible to detect the magnitude ofthe touch pressure by further including the pressure detection modulewhich detects the touch pressure.

FIG. 3 is a cross sectional view of the touch input device configured todetect the touch position and touch pressure in accordance with a firstembodiment of the present invention.

In the touch input device 1000 including the display module 200, thetouch sensor panel 100 and the pressure detection module 400 whichdetect the touch position may be attached on the front side of thedisplay module 200, As a result, the display screen of the displaymodule 200 can be protected and the touch detection sensitivity of thetouch sensor panel 100 can be improved.

Here, the pressure detection module 400 may be operated apart from thetouch sensor panel 100 which detects the touch position. For example,the pressure detection module 400 may be configured to detect only thetouch pressure independently of the touch sensor panel 100 which detectsthe touch position. Also, the pressure detection module 400 may beconfigured to be coupled to the touch sensor panel 100 which detects thetouch position and to detect the touch pressure. For example, at leastone of the drive electrode TX and the receiving electrode RX included inthe touch sensor panel 100 which detects the touch position may be usedto detect the touch pressure.

FIG. 3 shows that the pressure detection module 400 is coupled to thetouch sensor panel 100 and detects the touch pressure. In FIG. 3, thepressure detection module 400 includes a spacer layer 420 which leaves aspace between the touch sensor panel 100 and the display module 200. Thepressure detection module 400 may include a reference potential layerspaced from the touch sensor panel 100 by the spacer layer 420. Here,the display module 200 may function as the reference potential layer.

The reference potential layer may have any potential which causes thechange of the capacitance 101 generated between the drive electrode TXand the receiving electrode RX. For instance, the reference potentiallayer may be a ground layer having a ground potential. The referencepotential layer may be the ground layer of the display module 200. Here,the reference potential layer may have a parallel plane with thetwo-dimensional plane of the display module 200.

As shown in FIG. 3, the touch sensor panel 100 is disposed apart fromthe display module 200, i.e., the reference potential layer. Here,depending on a method for adhering the touch sensor panel 100 to thedisplay module 200, the spacer layer 420 may be implemented in the formof an air gap between the touch sensor panel 100 and the display module200. The spacer layer 420 may be made of an impact absorbing material inaccordance with the embodiment. The spacer layer 420 may be filled witha dielectric material in accordance with the embodiment.

Here, a double adhesive tape (DAT) 430 may be used to fix the touchsensor panel 100 and the display module 200. For example, the areas thetouch sensor panel 100 and the display module 200 are overlapped witheach other. The touch sensor panel 100 and the display module 200 areadhered to each other by adhering the edge portions of the touch sensorpanel 100 and the display module 200 through use of the DAT 430. Therest portions of the touch sensor panel 100 and the display module 200may be spaced apart from each other by a predetermined distance “d”.

In general, even when the touch surface is touched without bending thetouch sensor panel 100, the capacitance (Cm) 101 between the driveelectrode TX and the receiving electrode RX is changed. That is, whenthe touch occurs on the touch sensor panel 100, the mutual capacitance(Cm) 101 may become smaller than a base mutual capacitance. This isbecause, when the conductive object like a finger approaches close tothe touch sensor panel 100, the object functions as the ground GND, andthen a fringing capacitance of the mutual capacitance (Cm) 101 isabsorbed in the object. The base mutual capacitance is the value of themutual capacitance between the drive electrode TX and the receivingelectrode RX when there is no touch on the touch sensor panel 100.

When the object touches the top surface, i.e., the touch surface of thetouch sensor panel 100 and a pressure is applied to the top surface, thetouch sensor panel 100 may be bent. Here, the value of the mutualcapacitance (Cm) 101 between the drive electrode TX and the receivingelectrode RX may be more reduced. This is because the bend of the touchsensor panel 100 causes the distance between the touch sensor panel 100and the reference potential layer to be reduced from “d” to “d′”, sothat the fringing capacitance of the mutual capacitance (Cm) 101 isabsorbed in the reference potential layer as well as in the object. Whena nonconductive object touches, the change of the mutual capacitance(Cm) 101 is simply caused by only the change of the distance “d-d′”between the touch sensor panel 100 and the reference potential layer.

As described above, the touch input device 1000 is configured to includethe touch sensor panel 100 and the pressure detection module 400 on thedisplay module 200, so that not only the touch position but also thetouch pressure can be simultaneously detected.

However, as shown in FIG. 3, when the pressure detection module 400 aswell as the touch sensor panel 100 is disposed on the display module200, the display properties of the display module is deteriorated.Particularly, when the air gap 420 is included on the display module200, the visibility and optical transmittance of the display module maybe lowered.

Accordingly, in order to prevent such problems, the air gap is notdisposed between the display module 200 and the touch sensor panel 100for detecting the touch position. Instead, the touch sensor panel 100and the display module 200 can be completely laminated by means of anadhesive like an optically clear adhesive (OCA).

FIG. 4a is a cross sectional view of the touch input device according toa second embodiment of the present invention. In the touch input device1000 according to the second embodiment of the present invention, thecomplete lamination is made by an adhesive between the touch sensorpanel 100 and the display module 200 for detecting the touch position.As a result, the display color clarity, visibility and opticaltransmittance of the display module 200, which can be recognized throughthe touch surface of the touch sensor panel 100, can be improved.

In FIGS. 4a, 4b and 5 and the description with reference to FIGS. 4 and5, it is shown that as the touch input device 1000 according to thesecond embodiment of the present invention, the touch sensor panel 100is laminated and attached on the display module 200 by means of anadhesive. However, the touch input device 1000 according to the secondembodiment of the present invention may include, as shown in FIGS. 2band 2c , that the touch sensor panel 100 is disposed inside the displaymodule 200. More specifically, while FIGS. 4a, 4b and 5 show that thetouch sensor panel 100 covers the display module 200, the touch inputdevice 1000 which includes the touch sensor panel 100 disposed insidethe display module 200 and includes the display module 200 covered witha cover layer like glass may be used as the second embodiment of thepresent invention.

The touch input device 1000 according to the embodiment of the presentinvention may include an electronic device including the touch screen,for example, a cell phone, a personal data assistant (PDA), a smartphone, a tablet personal computer, an MP3 player, a laptop computer,etc.

In the touch input device 1000 according to the embodiment of thepresent invention, a substrate 300, together with an outermost cover 320of the touch input device 1000, functions as, for example, a housingwhich surrounds a mounting space 310, etc., where the circuit boardand/or battery for operation of the touch input device 1000 are placed.Here, the circuit board for operation of the touch input device 1000 maybe a main board. A central processing unit (CPU), an applicationprocessor (AP) or the like may be mounted on the circuit board. Due tothe substrate 300, the display module 200 is separated from the circuitboard and/or battery for operation of the touch input device 1000. Dueto the substrate 300, electrical noise generated from the display module200 can be blocked.

The touch sensor panel 100 or front cover layer of the touch inputdevice 1000 may be formed wider than the display module 200, thesubstrate 300, and the mounting space 310. As a result, the cover 320 isformed such that the cover 320, together with the touch sensor panel100, surrounds the display module 200, the substrate 300, and themounting space 310.

The touch input device 1000 according to the second embodiment of thepresent may detect the touch position through the touch sensor panel 100and may detect the touch pressure by disposing the electrodes 450 and460 for detecting a pressure between the display module 200 and thesubstrate 300. Here, the touch sensor panel 100 may be disposed insideor outside the display module 200. In the touch input device 1000according to the second embodiment of the present invention, the touchpressure can be detected by using the air gap and/or potential layerwhich are positioned inside or outside the display module 200 withoutmanufacturing a separate spacer layer and/or reference potential layer.This will be described in detail with reference to FIGS. 4b to 7 b.

FIG. 4b is an exemplary cross sectional view of the display module 200which can be included in the touch input device 1000 according to thesecond embodiment of the present invention. FIG. 4b shows an LCD moduleas the display module 200. As shown in FIG. 4b , the LCD module 200 mayinclude an LCD panel 200A and a backlight unit 200B. The LCD panel 200Acannot emit light in itself but simply performs a function to block ortransmit the light. Therefore, a light source is positioned in the lowerportion of the LCD panel 200A and light is illuminated onto the LCDpanel 200A, so that a screen displays not only brightness and darknessbut information with various colors. Since the LCD panel 200A is apassive device and cannot emit the light in itself, a light sourcehaving a uniform luminance distribution is required on the rear side.The structures and functions of the LCD panel 200A and the backlightunit 200B have been already known to the public and will be brieflydescribed below.

The backlight unit 200B for the LCD panel 200A may include severaloptical parts. In FIG. 4b , the backlight unit 200B may include a lightdiffusing and light enhancing sheet 231, a light guide plate 232, and areflection plate 240. Here, the backlight unit 200B may include a lightsource (not shown) which is formed in the form of a linear light sourceor point light source and is disposed on the rear and/or side of thelight guide plate 232. According to the embodiment, a support 233 may befurther included on the edges of the light guide plate 232 and the lightdiffusing and light enhancing sheet 231.

The light guide plate 232 may generally convert lights from the lightsource (not shown) in the form of a linear light source or point lightsource into light from a light source in the form of a surface lightsource, and allow the light to proceed to the LCD panel 200A.

A part of the light emitted from the light guide plate 232 may beemitted to a side opposite to the LCD panel 200A and be lost. Thereflection plate 240 may be positioned below the light guide plate 232so as to cause the lost light to be incident again on the light guideplate 232, and may be made of a material having a high reflectance.

The light diffusing and light enhancing sheet 231 may include a diffusersheet and/or a prism sheet. The diffuser sheet functions to diffuse thelight incident from the light guide plate 232. For example, lightscattered by the pattern of the light guide plate 232 comes directlyinto the eyes of the user, and thus, the pattern of the light guideplate 232 may be shown as it is. Moreover, since such a pattern can beclearly sensed even after the LCD panel 200A is mounted, the diffusersheet is able to perform a function to offset the pattern of the lightguide plate 232.

After the light passes through the diffuser sheet, the luminance of thelight is rapidly reduced. Therefore, the prism sheet may be included inorder to improve the luminance of the light by focusing the light again.

The backlight unit 200B may include a configuration different from theabove-described configuration in accordance with the technical changeand development and/or the embodiment. The backlight unit 200B mayfurther include an additional configuration as well as the foregoingconfiguration. Also, in order to protect the optical configuration ofthe backlight unit 200B from external impacts and contamination, etc.,due to the introduction of the alien substance, the backlight unit 200Baccording to the embodiment of the present may further include, forexample, a protection sheet on the prism sheet. The backlight unit 200Bmay also further include a lamp cover in accordance with the embodimentso as to minimize the optical loss of the light source. The backlightunit 200B may also further include a frame which maintains a shapeenabling the light diffusing and light enhancing sheet 231, the lightguide plate 232, a lamp (not shown), and the like, which are maincomponents of the backlight unit 200B, to be exactly combined togetherin accordance with an allowed dimension. Also, the each of thecomponents may be comprised of at least two separate parts. For example,the prism sheet may include two prism sheets.

Here, a first air gap 220-2 may be positioned between the light guideplate 232 and the reflection plate 240. As a result, the lost light fromthe light guide plate 232 to the reflection plate 240 can be incidentagain on the light guide plate 232 by the reflection plate 240. Here,between the light guide plate 232 and the reflection plate 240, for thepurpose of maintaining the air gap 220-2, a double adhesive tape 221-2may be included on the edges of the light guide plate 232 and thereflection plate 240.

Also, according to the embodiment, the backlight unit 200B and the LCDpanel 200A may be positioned with the second air gap 220-1 placedtherebetween. This intends to prevent that the impact from the LCD panel200A is transmitted to the backlight unit 200B. Here, between thebacklight unit 200B and the LCD panel 200A, a double adhesive tape 221-1may be included on the edges of the LCD panel 200A and the backlightunit 200B.

As described above, the display module 200 may be configured to includein itself the air gap such as the first air gap 220-2 and/or the secondair gap 220-1. Also, the air gap may be included between a plurality ofthe layers of the light diffusing and light enhancing sheet 231. In theforegoing, while the LCD module has been described, the air gap may beincluded within the structure of another display module.

Therefore, for detecting the touch pressure, the touch input device 1000according to the second embodiment of the present invention may make useof the air gap which has been already positioned inside or outside thedisplay module 200 without manufacturing a separate spacer layer. Theair gap which is used as the spacer layer may be not only the first airgap 220-2 and/or the second air gap 220-1 which are described withreference to FIG. 4b but also any air gap included inside the displaymodule 200. Also, the air gap which is used as the spacer layer may bean air gap included outside the display module 200. As such, themanufacture of the touch input device 1000 capable of detecting thetouch pressure reduces manufacturing cost and/or simplifies themanufacturing process.

FIG. 5 is a perspective view of the touch input device according to thesecond embodiment of the present invention. As shown in FIG. 5, thetouch input device 1000 according to the embodiment of the present mayinclude electrodes 450 and 460 which are disposed between the displaymodule 200 and the substrate 300 and detect the pressure. Hereafter, forthe purpose of clearly distinguishing the electrodes 450 and 460 fromthe electrode included in the touch sensor panel 100, the electrodes 450and 460 for detecting the pressure are designated as pressure electrodes450 and 460. Here, since the pressure electrodes 450 and 460 areincluded in the rear side instead of in the front side of the displaypanel, the pressure electrodes 450 and 460 may be made of an opaquematerial as well as a transparent material. FIG. 6a is a cross sectionalview of the touch input device including the pressure electrode patternaccording to the first embodiment of the present invention. As shown inFIG. 6a , between the display module 200 and the substrate 300, thepressure electrodes 450 and 460 according to the first embodiment of thepresent invention may be formed on the substrate 300. In FIGS. 6a to 6fand FIG. 7a , the pressure electrodes 450 and 460 are shownexaggeratedly thick for convenience of description. However, since thepressure electrodes 450 and 460 can be implemented in the form of asheet, the thickness of the first electrode 450 and the second electrode460 may be very small. Likewise, although the distance between thedisplay module 200 and the substrate 300 is also shown exaggeratedlylarge, the display module 200 and the substrate 300 may be implementedto have a very small distance therebetween. FIGS. 6a and 6b show thatthe display module 200 and the pressure electrodes 450 and 460 arespaced apart from each other so as to represent that the first electrode450 and the second electrode 460 have been formed on the substrate 300.However, this is for description only. The display module 200 and thefirst and second electrodes 450 and 460 may not be spaced apart fromeach other.

The pressure electrode for detecting the pressure may include the firstelectrode 450 and the second electrode 460. Here, any one of the firstand the second electrodes 450 and 460 may be a drive electrode and theother may be a receiving electrode. A driving signal is applied to thedrive electrode, and a sensing signal may be obtained through thereceiving electrode. When voltage is applied, the mutual capacitance maybe generated between the first electrode 450 and the second electrode460.

Here, FIG. 6a shows that the display module 200 includes a spacer layer220 and a reference potential layer 270.

The spacer layer 220 may be, as described with reference to FIG. 4b ,the first air gap 220-2 and/or the second air gap 220-1 which areincluded during the manufacture of the display module 200. When thedisplay module 200 includes one air gap, the air gap may function as thespacer layer 220. When the display module 200 includes a plurality ofair gaps, the plurality of air gaps may collectively function as thespacer layer 220. FIGS. 6a to 6c and FIG. 7a show that the displaymodule 200 functionally includes one spacer layer 220.

According to the embodiment of the present invention, the touch inputdevice 1000 may include the reference potential layer 270 which ispositioned above the spacer layer 220 within the display panel 200A ofFIGS. 2a to 2c . The reference potential layer 270 may be a groundpotential layer which is included in itself during the manufacture ofthe display module 200. For example, in the display panel 200A shown inFIGS. 2a to 2c , an electrode (not shown) for blocking the noise may beincluded between the first polarizer layer 271 and the first glass layer261. The electrode for blocking the noise may be composed of ITO and mayfunction as the ground. Within the display module 200, the referencepotential layer 270 may be located at any position causing the spacerlayer 220 to be placed between the reference potential layer 270 and thepressure electrodes 450 and 460. Not only the above-described blockingelectrode but also an electrode having any potential may be used as thereference potential layer 270. For example, the reference potentiallayer 270 may be a common electrode potential (Vcom) layer of thedisplay module 200.

Particularly, as part of an effort to reduce the thickness of the deviceincluding the touch input device 1000, the display module 200 may not besurrounded by a separate cover or frame. In this case, the bottomsurface of the display module 200, which faces the substrate 300, may bethe reflection plate 240 and/or a nonconductor. In this case, the bottomsurface of the display module 200 cannot have the ground potential. Asmentioned, even when the bottom surface of the display module 200 cannotfunction as the reference potential layer, it is possible to detect thetouch pressure by using any potential layer positioned within thedisplay module 200 as the reference potential layer 270 through use ofthe touch input device 1000 according to the embodiment of the presentinvention.

FIG. 6b is a cross sectional view of a case where a pressure has beenapplied to the touch input device 1000 shown in FIG. 6a . When thepressure is applied to the surface of the touch sensor panel 100 by theobject 500, the touch sensor panel 100 or the display module 200 may bebent or pressed. Here, the distance “d” between the reference potentiallayer 270 and the pressure electrode patterns 450 and 460 may bedecreased to “d′” by the spacer layer 220 positioned within the displaymodule 200. In this case, due to the decrease of the distance “d”, thefringing capacitance is absorbed in the reference potential layer 270,so that the mutual capacitance between the first electrode 450 and thesecond electrode 460 may be reduced. Therefore, the magnitude of thetouch pressure can be calculated by obtaining the reduction amount ofthe mutual capacitance from the sensing signal obtained through thereceiving electrode.

Here, when the magnitude of the touch pressure is sufficiently large, astate may be created in which the distance between the referencepotential layer 270 and the pressure electrode patterns 450 and 460 isnot reduced any more at a predetermined position. Hereafter, this statewill be referred to as a saturation state. However, even in this case,when the magnitude of the touch pressure becomes larger, an area in thesaturation state where the distance between the reference potentiallayer 270 and the pressure electrode patterns 450 and 460 is not reducedany more may become greater. The greater the area is, the more themutual capacitance between the first electrode 450 and the secondelectrode 460 may be reduced. Hereafter, it will be described that themagnitude of the touch pressure is calculated by the change of thecapacitance according to the distance change. However, this may includethat the magnitude of the touch pressure is calculated by the change ofthe area in the saturation state.

In the touch input device 1000 according to the embodiment of thepresent invention, the display module 200 may be bent or pressed by thetouch pressure. The display module 200 may be bent or pressed in such amanner as to show the biggest transformation at the touch position. Whenthe display module 200 is bent or pressed according to the embodiment, aposition showing the biggest transformation may not match the touchposition. However, the display module 200 may be shown to be bent orpressed at least at the touch position. For example, when the touchposition approaches close to the border, edge, etc., of the displaymodule 200, the most bent or pressed position of the display module 200may not match the touch position, however, the display module 200 may beshown to be bent or pressed at least at the touch position.

Here, when the display module 200 is bent or pressed at the time oftouching the touch input device 1000, the layer positioned below thespacer layer 220 (e.g., the reflection plate), as shown in FIG. 5e , maynot be bent or pressed or may be less bent or pressed due to the spacerlayer 220. While FIG. 5e shows that the lowest portion of the displaymodule 200 is not bent or pressed at all, this is just an example. Thelowest portion of the display module 200 may be bent or pressed.However, the degree to which the lowest portion of the display module200 is bent or pressed can be reduced by the spacer layer 220.

Here, the top surface of the substrate 300 may also have the groundpotential in order to block the noise. Therefore, in order to prevent ashort-circuit from occurring between the substrate 300 and the pressureelectrodes 450 and 460, the pressure electrodes 450 and 460 may beformed on an insulation layer 470. FIG. 8 shows an attachment structureof the pressure electrode according the embodiment of the presentinvention. Referring to (a) of FIG. 8, the first insulation layer 470 ispositioned on the substrate 300, and then the pressure electrodes 450and 460 are formed. Also, according to the embodiment, the firstinsulation layer 470 on which the pressure electrodes 450 and 460 havebeen formed may be attached on the substrate 300. Also, the pressureelectrode according to the embodiment may be formed by positioning amask, which has a through-hole corresponding to the pressure electrodepattern, on the substrate 300 or on the first insulation layer 470positioned on the substrate 300, and then by spraying a conductivematerial.

Also, when the bottom surface of the display module 200 has the groundpotential, the pressure electrodes 450 and 460 may be covered with anadditional second insulation layer 471 in order to prevent ashort-circuit from occurring between the display module 200 and thepressure electrode 450 and 460 positioned on the substrate 300. Also,the pressure electrodes 450 and 460 formed on the first insulation layer470 are covered with the additional second insulation layer 471 and thenare integrally attached on the substrate 300, so that the pressuredetection module 400 is formed.

The pressure electrode 450 and 460 attachment structure and method,which have been described with reference to (a) of FIG. 8, may beapplied to the attachment of the pressure electrodes 450 and 460 to thedisplay module 200. The attachment of the pressure electrodes 450 and460 to the display module 200 will be described in more detail withreference to FIG. 6 f.

Also, depending on the kind and/or implementation method of the touchinput device 1000, the substrate 300 or the display module 200 on whichthe pressure electrodes 450 and 460 are attached may not have the groundpotential or may have a weak ground potential. In this case, the touchinput device 1000 according to the embodiment of the present may furtherinclude a ground electrode (not shown) between the first insulationlayer 470 and either the substrate 300 or the display module 200.According to the embodiment, another insulation layer (not shown) may beincluded between the ground electrode and either the substrate 300 orthe display module 200. Here, the ground electrode (not shown) is ableto prevent the size of the capacitance generated between the firstelectrode 450 and the second electrode 460, which are pressureelectrodes, from increasing excessively.

The above-described method for forming and attaching pressure electrode450 and 460 can be applied in the same manner to the followingembodiments.

FIG. 6c is a cross sectional view of the touch input device includingthe pressure electrode pattern according to a modified example of thefirst embodiment of the present invention. FIG. 6c shows that the spacerlayer 220 is positioned between the display module 200 and the substrate300. When the touch input device 1000 including the display module 200is manufactured, the display module 200 is not completely attached tothe substrate 300, so that the air gap 420 may be created. Here, byusing the air gap 420 as the spacer layer for detecting the touchpressure, it is possible to reduce the time and cost intentionallyrequired for manufacturing the spacer layer for detecting the touchpressure. FIGS. 6c and 6d show that the air gap 420 used as the spacerlayer is not positioned within the display module 200. However, FIGS. 6cand 6d may additionally include a case where the air gap 420 ispositioned within the display module 200.

FIG. 6d is a cross sectional view of a case where a pressure has beenapplied to the touch input device shown in FIG. 6c . As with FIG. 6b ,when the touch occurs on the touch input device 1000, the display module200 may be bent or pressed. Here, the “d” between the referencepotential layer 270 and the pressure electrode patterns 450 and 460 maybe decreased to “d′” by the spacer layer 220 which are positionedbetween the reference potential layer 270 and the pressure electrodes450 and 460. In this case, a fringing capacitance is absorbed into thereference potential layer 270 due to the decrease of the distance “d”,so that the mutual capacitance between the first electrode 450 and thesecond electrode 460 may be reduced. As a result, the magnitude of thetouch pressure can be calculated by obtaining the reduction amount ofthe mutual capacitance from the sensing signal obtained through thereceiving electrode.

FIG. 6e is a cross sectional view of the touch input device including apressure electrode pattern according to the second embodiment of thepresent invention. While the first embodiment shows that the pressureelectrodes 450 and 460 are formed on the substrate 300, the pressureelectrodes 450 and 460 can be formed on the bottom surface of thedisplay module 200. The distance “d” between the reference potentiallayer 270 and the pressure electrodes 450 and 460 is reduced by touchingthe touch surface of the touch sensor panel 100. Consequently, this maycause the change of the mutual capacitance between the first electrode450 and the second electrode 460. FIG. 6e shows that the substrate 300and the pressure electrodes 450 and 460 are spaced apart from each otherso as to describe that the pressure electrodes 450 and 460 are attachedon the display module 200. However, this is for description only. Thesubstrate 300 and the pressure electrodes 450 and 460 may not be spacedapart from each other. Also, as with FIGS. 6c and 6d , the displaymodule 200 and the substrate 300 may be spaced apart from each other bythe air gap 420.

FIG. 6f shows the pressure electrode pattern according to the firstembodiment of the present invention. FIG. 6d shows that the firstelectrode 450 and the second electrode 460 are formed on the substrate300. The capacitance between the first electrode 450 and the secondelectrode 460 may be changed depending on the distance between thereference potential layer 270 and the pressure electrodes 450 and 460.

FIG. 6g shows the pressure electrode pattern according to the secondembodiment of the present invention. FIG. 6g shows that the pressureelectrode patterns 450 and 460 have been formed on the bottom surface ofthe display module 200.

FIGS. 6h and 6i show pressure electrode patterns 450 and 460 which canbe applied to the embodiment of the present invention. When themagnitude of the touch pressure is detected as the mutual capacitancebetween the first electrode 450 and the second electrode 460 is changed,it is necessary to form the patterns of the first electrode 450 and thesecond electrode 460 so as to generate the range of the capacitancerequired to improve the detection accuracy. With the increase of afacing area or facing length of the first electrode 450 and the secondelectrode 460, the size of the capacitance that is generated may becomelarger. Therefore, the pattern can be designed by adjusting the size ofthe facing area, facing length and facing shape of the first electrode450 and the second electrode 460 in accordance with the range of thenecessary capacitance. FIGS. 6h and 6i show that the first electrode 450and the second electrode 460 are formed in the same layer, and show thatthe pressure electrode is formed such that the facing length of thefirst electrode 450 and the second electrode 460 becomes relativelylonger.

The first and second embodiments show that the first electrode 450 andthe second electrode 460 are formed in the same layer. However, it canbe considered that the first electrode 450 and the second electrode 460are formed in different layers in accordance with the embodiment. It isshown in (b) of FIG. 8 that an attachment structure in which the firstelectrode 450 and the second electrode 460 are formed in differentlayers. As shown in (b) of FIG. 8, the first electrode 450 may be formedon the first insulation layer 470, and the second electrode 460 may beformed on the second insulation layer 471 positioned on the firstelectrode 450. According to the embodiment, the second electrode 460 maybe covered with a third insulation layer 472. Here, since the firstelectrode 450 and the second electrode 460 are disposed in differentlayers, they can be implemented so as to overlap each other. Forexample, the first electrode 450 and the second electrode 460 may beformed similarly to the pattern of the drive electrode TX and receivingelectrode RX which are arranged in the form of M×N array and areincluded in the touch sensor panel 100 described with reference toFIG. 1. Here, M and N may be natural numbers greater than 1.

The first embodiment shows that the touch pressure is detected from thechange of the mutual capacitance between the first electrode 450 and thesecond electrode 460. However, the pressure electrodes 450 and 460 maybe configured to include only any one of the first electrode 450 and thesecond electrode 460. In this case, it is possible to detect themagnitude of the touch pressure by detecting the change of thecapacitance between the one pressure electrode and the referencepotential layer 270.

For instance, in FIGS. 6a and 6c , the pressure electrode may beconfigured to include only the first electrode 450. Here, the magnitudeof the touch pressure can be detected by the change of the capacitancebetween the first electrode 450 and the reference potential layer 270,which is caused by the distance change between the reference potentiallayer 270 and the first electrode 450. Since the distance “d” is reducedwith the increase of the touch pressure, the capacitance between thereference potential layer 270 and the first electrode 450 may beincreased with the increase of the touch pressure. This can be appliedin the same manner to the embodiment related to FIG. 6e . Here, thepressure electrode should not necessary have a comb teeth shape or atrident shape, which is required to improve the detection accuracy ofthe mutual capacitance change amount. The pressure electrode may have aplate shape (e.g., quadrangular plate).

It is shown in (c) of FIG. 8c that an attachment structure in which thepressure electrode is formed to include only the first electrode 450. Asshown in (c) of FIG. 8, the first electrode 450 may be formed on thefirst insulation layer 470 positioned on the substrate 300 or displaymodule 200. Also, according to the embodiment, the first electrode 450may be covered with the second insulation layer 471.

FIG. 7a is a cross sectional view of the touch input device includingthe pressure electrode pattern according to a third embodiment of thepresent invention. The pressure electrodes 450 and 460 according to thethird embodiment may be formed on the top surface of the substrate 300and on the bottom surface of the display module 200.

The pressure electrode pattern for detecting the pressure may includethe first electrode 450 and the second electrode 460. Here, any one ofthe first electrode 450 and the second electrode 460 may be formed onthe substrate 300, and the other may be formed on the bottom surface ofthe display module 200. FIG. 7a shows that the first electrode 450 isformed on the substrate 300, and the second electrode 460 is formed onthe bottom surface of the display module 200. FIG. 7a shows that thefirst electrode 450 is spaced apart from the second electrode 460.However, this is just intended to describe that the first electrode 450is formed on the substrate 300 and the second electrode 460 is formed onthe display module 200. The first electrode 450 and the second electrode460 may be spaced apart from each other by the air gap, may have aninsulating material placed therebetween, or may be formed to deviatefrom each other, for example, may be formed in the same layer, not to beoverlapped with each other.

When the pressure is applied to the surface of the touch sensor panel100 by the object 500, the touch sensor panel 100 and the display module200 may be bent or pressed. As a result, the distance “d” between thereference potential layer 270 and the first and second electrodes 450and 460 may be reduced. In this case, the mutual capacitance between thefirst electrode 450 and the second electrode 460 may be decreased withthe reduction of the distance “d”. Therefore, the magnitude of the touchpressure can be calculated by obtaining the decrease amount of themutual capacitance from the sensing signal obtained through thereceiving electrode.

FIG. 7b shows the pressure electrode pattern according to the thirdembodiment of the present invention. FIG. 7b shows that the firstelectrode 450 is formed on the top surface of the substrate 300 and thesecond electrode 460 is formed on the bottom surface of the displaymodule 200. As shown in FIG. 7b , the first electrode 450 and the secondelectrode 460 are disposed perpendicular to each other, so that thecapacitance change amount detection sensitivity can be enhanced.

It is shown in (d) of FIG. 8 that an attachment structure in which thefirst electrode 450 is attached on the substrate 300 and the secondelectrode 460 is attached to the display module 200. As shown in (d) ofFIG. 8, the first electrode 450 may be positioned on the firstinsulation layer 470-2 formed on the substrate 300 and may be coveredwith the second insulation layer 471-2. Also, the second electrode 460may be positioned on the first insulation layer 470-1 formed on thebottom surface of the display module 200 and may be covered with thesecond insulation layer 471-1.

As with the description related to (a) of FIG. 8, when substrate 300 orthe display module 200 on which the pressure electrodes 450 and 460 areattached may not have the ground potential or may have a weak groundpotential, a ground electrode (not shown) may be further includedbetween the first insulation layers 470, 470-1, and 470-2 in (a) to (d)of FIG. 8. Here, an additional insulation layer (not shown) may befurther included between the ground electrode (not shown) and either thesubstrate 300 or the display module 200 on which the pressure electrodes450 and 460 are attached.

As described above, the touch input device 1000 according to theembodiment of the present invention senses the capacitance changeoccurring in the pressure electrodes 450 and 460. Therefore, it isnecessary for the driving signal to be applied to the drive electrodeout of the first and second electrodes 450 and 460, and it is requiredto detect the touch pressure by the capacitance change amount byobtaining the sensing signal from the receiving electrode. According tothe embodiment, it is possible to additionally include the touch sensingIC for the operation of the detection pressure. In this case, the touchinput device repeatedly has a configuration similar to the configurationof FIG. 1 including the drive unit 120, sensing unit 110, and controller130, so that the area and volume of the touch input device 1000increase.

According to the embodiment, for the purpose of detecting the pressure,the touch input device 1000 applies the driving signal for the operationof the touch sensor panel 100 through the touch detection device andreceives the sensing signal, so that the touch pressure can be detected.Hereafter, the following description will be provided by assuming thatthe first electrode 450 is the drive electrode and the second electrode460 is the receiving electrode.

For this, in the touch input device 1000 according to the embodiment ofthe present invention, the driving signal may be applied to the firstelectrode 450 from the drive unit 120, and the second electrode 460 maytransmit the sensing signal to the sensing unit 110. The controller 130may perform the scanning of the touch sensor panel 100, andsimultaneously perform the scanning of the touch pressure detection, orthe controller 130 performs the time-sharing, and then may generate acontrol signal such that the scanning of the touch sensor panel 100 isperformed in a first time interval and the scanning of the pressuredetection is performed in a second time interval different from thefirst time interval.

Therefore, in the embodiment of the present invention, the firstelectrode 450 and the second electrode 460 should be electricallyconnected to the drive unit 120 and/or the sensing unit 110. Here, it iscommon that the touch detection device for the touch sensor panel 100corresponds to the touch sensing IC 150 and is formed on one end of thetouch sensor panel 100 or on the same plane with the touch sensor panel100. The pressure electrode patterns 450 and 460 may be electricallyconnected to the touch detection device of the touch sensor panel 100 byany method. For example, the pressure electrode patterns 450 and 460 maybe connected to the touch detection device through a connector by usingthe second PCB 210 included in the display module 200. For example, asshown in FIG. 5, the conductive traces 451 and 461 which electricallyextend from the first electrode 450 and the second electrode 460respectively may be electrically connected to the touch sensing IC 150through the second PCB 210, etc.

FIGS. 9a and 9b show an attachment method of the pressure electrodeaccording the second embodiment of the present invention. FIGS. 9a and9b show that the pressure electrodes 450 and 460 according to theembodiment of the present invention are attached to the bottom surfaceof the display module 200. FIGS. 9a and 9b show the second PCB 210 onwhich a circuit for the operation of the display panel has been mountedis disposed on a portion of the bottom surface of the display module200.

FIG. 9a shows that the pressure electrode patterns 450 and 460 areattached to the bottom surface of the display module 200 such that thefirst electrode 450 and the second electrode 460 are connected to oneend of the second PCB 210 of the display module 200. Here, FIG. 9a showsthat the first electrode 450 and the second electrode 460 aremanufactured on the insulation layer 470. The first electrode pattern450 and the second electrode pattern 460 is formed on the insulationlayer 470 and may be attached as an integral sheet on the bottom surfaceof the display module 200. A conductive pattern may be printed on thesecond PCB 210 in such a manner as to electrically connect the pressureelectrode patterns 450 and 460 to a necessary component like the touchsensing IC 150, etc. The detailed description of this will be providedwith reference to FIGS. 10a to 10c . The attachment method of thepressure electrode patterns 450 and 460, which has been shown in FIG. 9a, can be applied in the same manner to the substrate 300.

FIG. 9b shows that the pressure electrodes 450 and 460 are integrallyformed on the second PCB 210 of the display module 200. For example,when the second PCB 210 of the display module 200 is manufactured, acertain area 211 is separated from the second PCB, and then not only thecircuit for the operation of the display panel but also the patterncorresponding to the first electrode 450 and the second electrode 460can be printed on the area 211. A conductive pattern may be printed onthe second PCB 210 in such a manner as to electrically connect the firstelectrode 450 and the second electrode 460 to a necessary component likethe touch sensing IC 150, etc.

FIGS. 10a to 10c show how the pressure electrode is connected to thetouch sensing IC 150 in accordance with the second embodiment of thepresent invention. In FIGS. 10a to 10c , the touch sensor panel 100 isincluded outside the display module 200. FIGS. 10a to 10c show that thetouch detection device of the touch sensor panel 100 is integrated inthe touch sensing IC 150 mounted on the first PCB 160 for the touchsensor panel 100.

FIG. 10a shows that the pressure electrodes 450 and 460 attached to thedisplay module 200 are connected to the touch sensing IC 150 through afirst connector 121. As shown in FIG. 10a , in a mobile communicationdevice such as a smart phone, the touch sensing IC 150 is connected tothe second PCB 210 for the display module 200 through the firstconnector 121. The second PCB 210 may be electrically connected to themain board through a second connector 221. Therefore, through the firstconnector 121 and the second connector 221, the touch sensing IC 150 maytransmit and receive a signal to and from the CPU or AP for theoperation of the touch input device 1000.

Here, while FIG. 10a shows that the first electrode 450 is attached tothe display module 200 by the method shown in FIG. 9b , the firstelectrode 450 can be attached to the display module 200 by the methodshown in FIG. 9a . A conductive pattern may be printed on the second PCB210 in such a manner as to electrically connect the first electrode 450and the second electrode 460 to the touch sensing IC 150 through thefirst connector 121.

FIG. 10b shows that the pressure electrodes 450 and 460 attached to thedisplay module 200 are connected to the touch sensing IC 150 through athird connector 471. In FIG. 10b , the pressure electrodes 450 and 460may be connected to the main board for the operation of the touch inputdevice 1000 through the third connector 471, and in the future, may beconnected to the touch sensing IC 150 through the second connector 221and the first connector 121. Here, the pressure electrodes 450 and 460may be printed on the additional PCB 211 separated from the second PCB210. Otherwise, according to the embodiment, the pressure electrodepatterns 450 and 460 may be formed on the insulation layer 470 and maybe connected to the main board through the connector 471 by extendingthe conductive trace, etc., from the pressure electrodes 450 and 460.

FIG. 10c shows that the pressure electrode patterns 450 and 460 aredirectly connected to the touch sensing IC 150 through a fourthconnector 472. In FIG. 10c , the pressure electrodes 450 and 460 may beconnected to the first PCB 160 through the fourth connector 472. Aconductive pattern may be printed on the first PCB 160 in such a manneras to electrically connect the fourth connector 472 to the touch sensingIC 150. As a result, the pressure electrodes 450 and 460 may beconnected to the touch sensing IC 150 through the fourth connector 472.Here, the pressure electrodes 450 and 460 may be printed on theadditional PCB 211 separated from the second PCB 210. The second PCB 210may be insulated from the additional PCB 211 so as not to beshort-circuited with each other. Also, according to the embodiment, thepressure electrodes 450 and 460 may be formed on the insulation layer470 and may be connected to the first PCB 160 through the connector 472by extending the conductive trace, etc., from the pressure electrodes450 and 460.

The connection method of FIGS. 10b and 10c can be applied to the casewhere the pressure electrodes 450 and 460 are formed on the substrate300 as well as on the bottom surface of the display module 200.

FIGS. 10a to 10c have been described by assuming that a chip on board(COB) structure in which the touch sensing IC 150 is formed on the firstPCB 160. However, this is just an example. The present invention can beapplied to the chip on board (COB) structure in which the touch sensingIC 150 is mounted on the main board within the mounting space 310 of thetouch input device 1000. It will be apparent to those skilled in the artfrom the descriptions of FIGS. 10a to 10c that the connection of thepressure electrodes 450 and 460 through the connector can be alsoapplied to another embodiment.

The foregoing has described the pressure electrodes 450 and 460, that isto say, has described that the first electrode 450 constitutes onechannel as the drive electrode and the second electrode 460 constitutesone channel as the receiving electrode. However, this is just anexample. According to the embodiment, the drive electrode and thereceiving electrode constitute a plurality of channels respectively, sothat a plurality of pressure detection can be made based on themulti-touch.

FIGS. 11a to 11c show that the pressure electrode according to theembodiment of the present invention constitutes the plurality ofchannels. FIG. 11a shows the first electrode 450-1 and 450-2 and thesecond electrode 460-1 and 460-2 constitute two channels respectively.FIG. 11b shows that the first electrode 450 constitutes two channels450-1 and 450-2 and the second electrode 460 constitutes one channel.FIG. 11c shows the first electrode 450-1 to 450-5 and the secondelectrode 460-1 to 460-5 constitute five channels respectively.

FIGS. 11a to 11c show that the pressure electrode constitutes a singleor a plurality of channels. The pressure electrode may be comprised of asingle or a plurality of channels by a variety of methods. While FIGS.11a to 11c do not show that the pressure electrodes 450 and 460 areelectrically connected to the touch sensing IC 150, the pressureelectrodes 450 and 460 can be connected to the touch sensing IC 150 bythe method shown in FIGS. 10a to 10c and other methods.

FIG. 12 is a graph that, when an experiment where the central portion ofthe touch surface of the touch input device 1000 according to theembodiment of the present invention is pressed by the non-conductiveobject is performed, represents a capacitance change amount according toa gram force of the object. As shown in FIG. 12, the greater the forcewhich is applied to the central portion of the touch surface of thetouch input device 1000 according to the embodiment of the presentinvention, the greater the capacitance change amount of the pressureelectrode patterns 450 and 460 for detecting the pressure.

The foregoing has described the capacitance type detection module fordetecting the pressure. However, so long as the spacer layer 420 and 220and the pressure electrodes 450 and 460 are used to detect the pressure,the touch input device 1000 according to the embodiment of the presentis able to use any type pressure detection module.

Although embodiments of the present invention were described above,these are just examples and do not limit the present invention. Further,the present invention may be changed and modified in various ways,without departing from the essential features of the present invention,by those skilled in the art. For example, the components described indetail in the embodiments of the present invention may be modified.Further, differences due to the modification and application should beconstrued as being included in the scope and spirit of the presentinvention, which is described in the accompanying claims.

What is claimed is:
 1. A smartphone comprising: a cover layer; an LCDpanel which is located under the cover layer and comprises a liquidcrystal layer, and a first glass layer and a second glass layer betweenwhich the liquid crystal layer is placed, wherein a touch sensor whichsenses touch in a capacitive manner is at least partially locatedbetween the first glass layer and the second glass layer; a backlightunit which is located under the LCD panel; a pressure electrode which islocated under the backlight unit; and a substrate located under thepressure electrode to shield electrical noise, wherein the touch sensorcomprises a plurality of drive electrodes and a plurality of receivingelectrodes, wherein a drive signal is applied to the touch sensor and atouch position is detected by a sensing signal which is outputted fromthe touch sensor, wherein a reference potential layer is located withina display module comprising the LCD panel and the backlight unit,wherein a touch pressure bends the display module, wherein a magnitudeof the touch pressure is detected based on a change amount ofcapacitance outputted from the pressure electrode, and wherein thechange amount of the capacitance outputted from the pressure electrodechanges according to a distance between the pressure electrode and thereference potential layer and changes as the display module bends. 2.The smartphone of claim 1, wherein the touch sensor includes at leastone of the drive electrode and the receiving electrode located betweenthe first glass layer and the second glass layer.
 3. The smartphone ofclaim 1, wherein the LCD panel further comprises a first polarizer layerand a second polarizer layer between which the first glass layer, theliquid crystal layer and the second glass layer are placed, and whereinat least a portion of the touch sensor is located between the firstglass layer and the first polarizer layer.
 4. The smartphone of claim 1,further comprising a spacer layer which is located between the pressureelectrode and the reference potential layer.
 5. The smartphone of claim1, wherein the pressure electrode comprises a plurality of electrodesconstituting a plurality of channels.
 6. The smartphone of claim 1,wherein the reference potential layer is one of a ground layer withinthe display module or a common electrode potential layer within thedisplay module.
 7. A smartphone comprising: a cover layer; an LCD panelwhich is located under the cover layer and comprises a liquid crystallayer, and a first glass layer and a second glass layer between whichthe liquid crystal layer is placed, wherein a touch sensor which sensestouch in a capacitive manner is at least partially located between thefirst glass layer and the second glass layer; a backlight unit which islocated under the LCD panel and comprises a reflection plate; a pressureelectrode which is located under the backlight unit; and a substratelocated under the pressure electrode to shield electrical noise, whereinthe touch sensor comprises a plurality of drive electrodes and aplurality of receiving electrodes, and further comprising: a drive unitwhich applies a drive signal to the touch sensor; a sensing unit whichreceives a sensing signal from the touch sensor and detects a touchposition; and wherein a reference potential layer is located within adisplay module comprising the LCD panel and the backlight unit, whereina touch pressure bends the display module, a pressure detector whichdetects a magnitude of the touch pressure based on a change amount ofcapacitance outputted from the pressure electrode, and wherein thechange amount of the capacitance outputted from the pressure electrodechanges according to a distance between the pressure electrode and thereference potential layer and changes as the display module bends. 8.The smartphone of claim 7, wherein the touch sensor includes at leastone of the drive electrode and the receiving electrode located betweenthe first glass layer and the second glass layer.
 9. The smartphone ofclaim 7, wherein the LCD panel further comprises a first polarizer layerand a second polarizer layer between which the first glass layer, theliquid crystal layer and the second glass layer are placed, and whereinat least a portion of the touch sensor is located between the firstglass layer and the first polarizer layer.
 10. The smartphone of claim7, further comprising a spacer layer which is located between thepressure electrode and the reference potential layer.
 11. The smartphoneof claim 7, wherein the pressure electrode comprises a plurality ofelectrodes constituting a plurality of channels.
 12. The smartphone ofclaim 7, wherein the reference potential layer is one of a ground layerwithin the display module or a common electrode potential layer withinthe display module.
 13. A smartphone comprising: a cover layer; an LCDpanel which is located under the cover layer and comprises a liquidcrystal layer, and a first glass layer and a second glass layer betweenwhich the liquid crystal layer is placed, wherein a touch sensor whichsenses touch in a capacitive manner is at least partially locatedbetween the first glass layer and the second glass layer; a backlightunit which is located under the LCD panel; a pressure electrode which islocated under the backlight unit; and a reference potential layer spacedfrom the pressure electrode, wherein the touch sensor comprises aplurality of drive electrodes and a plurality of receiving electrodes,wherein a drive signal is applied to the touch sensor and a touchposition is detected by a sensing signal which is outputted from thetouch sensor, wherein the reference potential layer is located within adisplay module comprising the LCD panel and the backlight unit, whereina touch pressure bends the display module, wherein a magnitude of thetouch pressure is detected based on a change amount of capacitanceoutputted from the pressure electrode, and wherein the change amount ofthe capacitance outputted from the pressure electrode changes accordingto a distance between the pressure electrode and the reference potentiallayer and changes as the display module bends.
 14. The smartphone ofclaim 13, wherein the touch sensor includes at least one of the driveelectrode and the receiving electrode located between the first glasslayer and the second glass layer.
 15. The smartphone of claim 13,wherein the LCD panel further comprises a first polarizer layer and asecond polarizer layer between which the first glass layer, the liquidcrystal layer and the second glass layer are placed, and wherein atleast a portion of the touch sensor is located between the first glasslayer and the first polarizer layer.
 16. The smartphone of claim 13,further comprising a spacer layer which is located between the pressureelectrode and the reference potential layer.
 17. The smartphone of claim13, wherein the pressure electrode comprises a plurality of electrodesconstituting a plurality of channels.
 18. The smartphone of claim 13,wherein the reference potential layer is one of a ground layer withinthe display module or a common electrode potential layer within thedisplay module.
 19. A smartphone comprising: a cover layer; a displaymodule comprising: an LCD panel located under the cover layer andcomprising a liquid crystal layer, a first glass layer, and a secondglass layer, the liquid crystal layer located between the first andsecond glass layers; a backlight unit which is located under the LCDpanel; a reference potential layer; and a spacer layer comprising an airgap located between the pressure electrode and the reference potentiallayer, a touch sensor comprising a plurality of drive electrodes and aplurality of receiving electrodes configured to sense a touch on thecover layer through changes in capacitance, the touch sensor being atleast partially located between the first and second glass layers of theLCD panel, wherein a drive signal is applied to the touch sensor, and inresponse to the touch at a touch position on the cover layer, a sensingsignal representative of the touch and the touch position is output fromthe touch sensor; a substrate located under the backlight unit; and apressure electrode located on the substrate between the substrate andthe backlight unit, the substrate shielding the pressure electrode fromelectrical noise; wherein in response to a touch pressure bending thedisplay module and moving the reference potential layer closer to thepressure electrode, the pressure electrode outputs a change amount ofcapacitance; wherein a magnitude of the touch pressure is detected basedon the change amount of the capacitance; and wherein the change amountof the capacitance output from the pressure electrode changes accordingto a distance between the reference potential layer and the pressureelectrode as the touch pressure bends the display module.
 20. Thesmartphone of claim 19, wherein one of the LCD panel or the backlightunit comprises the reference potential layer of the display module. 21.The smartphone of claim 19, wherein the pressure electrode is formed asa single layer on the substrate.